Electric switching mechanism.



F. B. LITTLE.

ELECTRIC SWITCHING MECHANISM.

APPLICATlON FILED MAR. I3, |916. 1,228,222. Patented May 29,1917.

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y ZZ

F. B. LITTLE.

ELECTRIC SWITCHING NIE-CHAN|SNL APPLICATION FILED MAR. 13. |916. N1,228,222. Patented May 29,191..

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' STATES PATENT OFFICE.

l FREDERICK B. LITTLE, F CHICAGO, ILLINOIS, ASSIGNOR, BY MESNEASSIGNMENTS, TO Jg C. DEAGAN'MUSICAL IBELLS, 0F CHICAGO, ILLINOIS, ACORPORATION 0F ILLINOIS.

' '15 sound produei-n devices that have electromagnets forl e ectingtheir operation and Ahas for its object the provision of improvedSwitching mechanism that is operable by l the keys and Iwhereby injuredAswitches may readily be removed and replaced without dismounting thekeys. The'importance ofl 4 vmy invention will be appreciated-when it is`understood that' switches frequently break down during amusicalperformance, hither- Kto requiring mulch time in repair whereas by the4device of my invention -an injuredvv Switch\may be instantly re laced.In the preferred embodiment'of-the invention I provide a mounting stripat the 'rear of the keyboard, this mountin strip carrying a pluralityof, pairs of seria ly re-4 lated contacts, there being one pair of 4suchcontacts individual to each sound producing device. Each pair ofcontacts has a pair of .serially related complemcntal contacts, the

a pairs of complemental contacts being mountt ed upon separate carriers.TheJ contacts of elac'hpair has separable engagement with'the contactsof the pair complemental thereto', a

l 4Qplugand jack formation of the interengaging .contacts beingpreferably.. employed whereby the pair of complemental contacts mountedupon separate carriers may readily7 be engaged with the contactscarriedby the mounting strip. Each key has a pair of separable ncontactsindividual thereto and carries a switch operator for bringing suchcontacts electrically together, this switch /operator being desirably inthe nature of al ,50 stiff leaf spring operating upon one contactSpecivcation of Letters Tatent.

,thimble constituting a jack), a split pin\9 ELECTRIC SWITCHINGMEHANIsM.

Patented May 29, 1917.

- u Application 111e@ March 13,1916. Serial No. 88,774.

to force it against its companion, the rst contact being desirably inthe 'form' of a leaf spring which will automatically separate from itscompanion when the corresponding key is released. I will explain myinvention more fully by reference to the accompanying drawings showingthepreferred embodiment thereof and in which Figure 1 diagrammaticallyillustrates 'the preferred embodiment of the 60 invention; Fig. 2 is aplan view of a part of a bank vof keys and associated switchingmechanism; and Fig. 3 is a sectional view 0n line 3-3 of Fig. 2. t

Like parts are indicated by similar characters of reference throughoutthe different figures. The soundproducing devices illustrated in Fig. 1include each an operating magnet 1 adapted for inclusion in bridgebetween70 the sides 2 and3 of a supply circuit furnished with current bya battery 4 also in bridge between these sides. Each magnet containingbridge may be traced from the side 2 of the supply circuit through thecon- 75 tact 5, the contact 6 normally engaging con- .tact 5, thewinding of the magnet, the contact screw 7, the contact thimble 8 intowhich the screw is threaded (this contact constituting a plugfor-reception within the jack 8, theleaf spring 10, al contact l1complemental to the spring 10 and fromrwhich the spring 10 is normallyseparated due toI the resilience ofsuch spring, a' screw 12, a 85contact thimble 13 into which the screw 12 is threaded (this contactim-bleconstituting a jack), a split pin '14 onstituting a plugforreception within the jack 13, to the other side 3 of the supplycircuit. Thel conductors 9.0

x which lead from the magnets V1 to the screws 7 kare included in acable 15 lthat is disposedbeneath'a mounting strip, this mounting stripbeing separably secured to the back of the keyboard cabinet by screws17. The contacts 8 and 14l are mounted upon the mounting strip 16, thecontacts 14 being in common connection -as they are desirably mountedvupon a conductingstrip 18. The contacts 8, however, are electricalyseparate, 10Q

being individual to the 'magnetsv 1 and the sound producing bars19-individual to such cal continuations 10 and 11:.of the contactsr 9and 13 are,- of course, bodily movable with 20 carried by the v1n thecontacts 9 and 13 as '.tley are mounted upon the same carrier. T. eseelements 10 a-nd 11 themselves constitute a switch, such switchesprojecting, at their forward ends, over the rear ends of the manual keys22 which are desirably black and white and correspond in arrangement tothe keys of a piano. Each l'manual key 22 carries a switch actuator oroperator 23 that is desirably in the form of a stiff spring fingerterminating at its upper end beneath andl 1n contact with the sprmcontact 10; the arrangement of the parts eing such that theuspringcontact 10 will disengage itself from the contact 11 when the associatekey 22 is in normal position or is not suiciently depressed to cause thefinger 23 to move the contact 10 into engagement'with the contact 11.The spring 1Q also desirably exerts restoring force upon the key 22underlying it though this function is preferably supplemented by theaction. of ah additional spring 24. -The rear ends of the inanual keysand the switching -mechanism are normally covered by the hinged lid 25that may be swun back when access is to be had to the switc ing mechalnism.

rlfhe operation ofthe instrument be readily understood from theforegoing de! scriptlon of the` drawin The sound producing bars- 19 areindividual to different keys 22 and the magnets 1 to which such keys areindividual and asjthese bars are desirably arranged in a chromatic scalesufv ficient depression of the keys will cause the corresponding bars tovibrate 'in the order in which the'keys are operated. Hitherto theswitches controlled by the keys have been so mounted as to render them-rdiiicult of access and as to require'much time to.

effect their removaland replacement so that if any of the switches brokeldown during a performance such performance would likely have to bediscontinued. If the contacts 10 and 11 of any switch should becomeinjured as a consequence of'sparking or otherwise, the .carrier 21 forsuch contacts may be quickly removed and a new /carrier with similarcontacts may readilybe put into the position of the removed `carrierwith the contacts 9 and 13 engaging the fixed c0n ,615

the preferred embodiment 4 N parting from the spirit ofmy invention, butv `having thus described my inventin I claim as new and desire to secureby Letters Patent the followng:-,

1. The combination lwith a bank of man- *ual keys of switches, eachindividualto al manual ey and located over 'the rear end thereof andhaving a movable contact-memberinterposed between the keyand the contactcomplemental to such contact-member; switch-actuating members upon thekeys and projecting upwardly into en agement with said movablecontact-mem ers and serving to bring these movable contactmembers intoengagement with their complemental contacts when the keys are depressed;individual carriers for said switches; a mounting for saidcarriers; andconnecting switches for connecting the aforesaid switches and havingseparable complemental parts upon the mounting and carriers.

2. The combination with a bank of manual keys; of switches, eachindividual to a manual key; switch actuatingmembers upon the'keysandengaging mova le members of the switches; individual carriers forsaid switches; a mounting for sa/id carriers; and

' connecting switches for connecting the aforesaid switches and havingvseparable complemental parts upon the mounting and carriers. v

3. The combination with a bank of man# ual vkeys that are eachindividual to a. sound producing device; of switches,` each indi-`vidual to a manual key and operable therev by; individual carriers forsaid switches; a mounting for said carriers; and connectin switcheshaving separable complemen parts upon the mounting and carriers.

4. The combination with a bank of man- -ual keys that areeach individualto a sound ual carriers for said -switches; and.l a niountf 5 .ingfonthe cairiers upon which such carriers v, are sepxu'ably supported.

[In wltness whereof, I helleunto subsoribe lily .na-me -thistwenty-sixth dag-vv of Feli- .ruery, A. D. 1916. I

y* FREDERICK B. LITTLE.

' Witnessesz- I G. L. Gmac, Erm L. Wm.

